Arc faults in medium-voltage switchgear assemblies are generally to be extinguished as quickly as possible. Protection devices for this purpose can have an arc-fault duration of 200 to 300 milliseconds, which is extinguished by actuation of a feed circuit breaker. However, for long arc-fault durations, the switchgear assembly can be damaged. Fast-acting protection relays reduce the arc-fault duration to 50 to 100 milliseconds using current limiters. However, this is still too long.